update modal header linelimit when larger sizes

When the header contains longer text that fits on screen, is cut to max 1 line only, we can remove the limit for larger sizes so all text is visible

Author: iamgabrielma

WooCommerce/Classes/POS/Presentation/PointOfSaleModalHeader.swift

@@ -1,14 +1,17 @@
 import SwiftUI
 
 struct PointOfSaleModalHeader: View {
+    @Environment(\.dynamicTypeSize) private var dynamicTypeSize
+
     @Binding var isPresented: Bool
     @Binding var title: AttributedString
 
     var body: some View {
         HStack {
             Text(title)
                 .font(.posHeadingBold)
-                .lineLimit(1)
+                .dynamicTypeSize(...DynamicTypeSize.accessibility2)
+                .lineLimit(dynamicTypeSize.isAccessibilitySize ? nil : 1)
             Spacer()
             Button {
                 isPresented = false